I will totally second that approach. Rather spending time on reading code line by line, you should have your team spend time (as a tester) to figure out use-cas

I will totally second that approach. Rather spending time on reading code line by line, you should have your team spend time (as a tester) to figure out use-cases. One by one. The end result of those use-cases should be a user-case/requirement document which you can feed into developers cycles to start building from scratch. You can break the steps in more agile method and have 3 sub-teams. 1. Figuring out use cases 2. Developers 3. Testers